Cross reference is made to two U.S. patent applications: Ser. No. 044/761, now U.S. Pat. No. 5,082,627 for Three Dimensional Binding Site Array For Interfering With An Electrical Field, by W. D. Stanbro; and Ser. No. 044,769, now U.S. Pat. No. 4,769,121 for Sintered Pellet With Biochemically Active Layer, by A. L. Newman, which were filed the same date and were assigned to the same entity as this application.
The invention relates to a means for interfering with an electrical field. More specifically, the invention relates to an electrode insulated with an added array of molecular chains.
In composition analysis, capacitive sensors have been used to determine the concentration of a specific gas in a mixture, or an analyte in a fluid, for example. Such sensors measure a capacitance that changes with that concentration.
Newman U.S. patent application Ser. No. 799,761, filed Nov. 19, 1985, and now abandoned, ("the Newman Patent Application") involves a capacitor for determining the concentration of an analyte in a fluid, for instance. Biospecific binding reactions occur in a space between electrodes of a capacitive sensor. These reactions occur among molecules of a binding agent immobilized on a surface and an analyte in a fluid. These reactions result in the displacement of small fluid molecules having high dielectric constants by large biochemical molecules having low-dielectric constants. This displacement of molecules changes the dielectric properties of the capacitor.
Raymond et al. U.S. Pat. No. 4,571,543 discusses a capacitor for detecting and measuring the concentration of specific non-aqueous materials or constituents in fluids. The capacitor is layered with a coating of silane and then a coating of certain polymers. These polymers form membranes that are permeable to constituents of the fluids. The constituents penetrate through the membrane to change the dielectric constant of a solution in the membrane.
Volgyesi U.S. Pat. No. 4,453,126 concerns a capacitor for monitoring the concentration of anaesthetic gas in a breathing mixture. The capacitor has a dielectric of lipids or elastomers which permit the absorption of the anaesthetic gas to vary electrical characteristics of the sensor.
"Adsorption Of Blood Proteins On Metals Using Capacitance Techniques", by Stoner et al., The Journal of Physical Chemistry, Vol. 74, No. 5, Mar. 5, 1970, describes a differential capacity method for measuring adsorption of proteins on solid metal electrodes.
Arwin et al. U.S. Pat. No. 4,072,576 relates to a capacitive method for studying enzymatic activity and for studying an immunological reaction. An adsorbed polypeptide substrate is used in studying enzymatic activity and an antigen is adsorbed onto an electrode surface in studying the reaction of the antigen with an antibody.